How do 'alpha-compositing' and 'blend-mode' interact if you have set both? I was unable to determine this from the spec. Does it actually make sense to specify both to non-default values at the same time? I was unable to understand what their relationship is supposed to be.
Some other comments:
- The property values for the 'alpha-compositing' operator are inconsistent with the values for HTML5 Canvas: <http://www.w3.org/TR/2dcontext/#dom-context-2d-globalcompositeoperation>. I suggest making them match if there is no compelling advantage to the new names, otherwise this will be needlessly confusing to authors.
- Consider renaming 'alpha-compositing' to 'composite-operator' for similar reasons.
Regards,
Maciej